Rapid exchange fluid jet catheter and method

ABSTRACT

Catheters including guidewire tubes having a limited length and methods of using the catheters are described. The catheters may be delivered over guidewires in procedures that are commonly referred to as rapid-exchange delivery. In some embodiments, the catheters may be miniature flexible thrombectomy catheters that may be used to remove thrombus or other unwanted material from a body blood vessel or other small regions of body cavities in which the distal portion of the catheter has smaller external dimensions than the larger proximal portion

RELATED APPLICATION

The present application claims the benefit under 35 U.S.C. §119(e) ofU.S. Provisional Patent Application No. 61/183,642, filed on Jun. 3,2009 and titled RAPID EXCHANGE FLUID JET CATHETER AND METHOD, which ishereby incorporated by reference in its entirety.

Rapid exchange catheters including guidewire tubes and methods of usingthe same are described herein.

Catheters may be used for a variety of procedures. Some catheters,typically referred to as thrombectomy catheters, may be used to performprocedures in which thrombotic material is removed from a blood vessel(or other body lumen). The removed material may preferably be removedfrom the body through the thrombectomy catheter.

Examples of some thrombectomy catheters are described in, e.g., U.S.Patent Application Publication US 2008/0188831 A1, titled MINIATUREFLEXIBLE THROMBECTOMY CATHETER (Bonnette et al.); U.S. Pat. No.6,875,193 (Bonnette et al.); U.S. Pat. No. 6,805,684 (Bonnette et al.);U.S. Pat. No. 6,755,803 (Le et al.); U.S. Patent Application PublicationUS 2006/0064123 A1 (Bonnette et al.); U.S. Patent ApplicationPublication No. US 2007/0129679 (Bonnette et al.); etc.

SUMMARY

Catheters including guidewire tubes having a limited length and methodsof using the catheters are described herein. The catheters may bedelivered over guidewires in procedures that are commonly referred to asrapid-exchange delivery. In some embodiments, the catheters may beminiature flexible thrombectomy catheters that may be used to removethrombus or other unwanted material from a body blood vessel or othersmall regions of body cavities in which the distal portion of thecatheter has smaller external dimensions than the larger proximalportion.

The guidewire tubes used in the catheters described herein preferablyterminate at locations that are located proximally from the distal endsof the catheters. The guidewire tubes may preferably terminate at adistal end that is located proximally from a fluid jet emanator that isprovided within an exhaust lumen of the catheter.

In some embodiments, the catheters may include a distal body sectionthat has a smaller cross-sectional size than a proximal body section towhich the distal body section is attached. An exhaust lumen provided inthe catheter to remove fluid delivered through the fluid jet emanatormay also have a smaller cross-sectional area in the smaller distal bodysection than in the larger proximal body section. It may be preferredthat the distal end of the guidewire tube terminate within the portionof the exhaust lumen located in the proximal body section such that theguidewire tube does not constrict the size of the exhaust lumen in thesmaller distal body section of the catheter. In some embodiments,however, beneficial results can be achieved if the guidewire tubeextends into the exhaust lumen of the distal body section, butterminates at or proximal to the fluid jet emanator contained within thedistal catheter body section.

In some embodiments, the guidewire tube may be fixed within the cathetersuch that it remains in place throughout use of the catheter. In otherembodiments, the guidewire tube may be removed from the catheter afterhaving accomplished the function of guiding a guidewire through thecatheter during advancement of the catheter to a selected internal bodylocation.

In one aspect, the catheters described herein may include an elongatedcatheter body having a proximal end and a distal end, wherein alongitudinal axis extends between the proximal end and the distal end,and wherein the catheter body includes a proximal body section and adistal body section, wherein a distal end of the proximal body sectionis attached to a proximal end of the distal body section at a transitionsection of the catheter body; an exhaust lumen located within thecatheter body, the exhaust lumen being aligned with the longitudinalaxis, wherein the exhaust lumen has a proximal cross-sectional area on aproximal side of the transition section that is larger than a distalcross-sectional area of the exhaust lumen on a distal side of thetransition section; a fluid jet emanator located in the distal bodysection; a fluid delivery tube attached to the fluid jet emanator, thefluid delivery tube extending through at least a portion of the proximalbody section, wherein the fluid delivery tube passes from the proximalbody into the distal body section through the transition section; and aguidewire tube located within only a portion of the catheter body,wherein the guidewire tube has a proximal end and a distal end, whereinthe guidewire tube comprises a guidewire lumen extending from a proximalport at the proximal end of the guidewire tube to a distal port at thedistal end of the guidewire tube, and wherein the distal port of theguidewire lumen opens into the exhaust lumen at a location proximal fromthe fluid jet emanator.

In some embodiments, the distal end of the guidewire tube is locatedbetween the proximal end of the distal body section and the proximal endof the guidewire tube.

In some embodiments, the proximal end of the guidewire tube is locatedin the proximal body section of the catheter body and the distal end ofthe guidewire tube is located between the proximal end of the distalbody section and the proximal end of the guidewire tube.

In some embodiments, the proximal end of the guidewire tube is locatedin the proximal body section of the catheter body.

In some embodiments, the proximal end of the guidewire tube is locatedin the proximal body section of the catheter body and the distal end ofthe guidewire tube is located in the transition section.

In some embodiments, the catheters described herein may include one ormore protrusions extending into the exhaust lumen in a directiontransverse to the longitudinal axis.

In some embodiments, the distal end of the guidewire lumen is flaredsuch that the distal port of the guidewire lumen is enlarged in adirection transverse to the longitudinal axis.

In some embodiments, the fluid jet emanator includes a guidewireorifice, such that a guidewire directed into the exhaust lumen from thedistal end of the catheter body and advanced proximally toward theproximal end of the catheter body passes through the guidewire orificebefore entering the distal port of the guidewire lumen.

In some embodiments, the catheter body includes a guidewire tube portthat includes a seal, wherein the guidewire tube extends through theseal of the guidewire tube port and into the exhaust lumen, and whereinthe seal restricts fluid flow out of the exhaust lumen through theguidewire port around the guidewire tube.

In some embodiments in which the catheter body includes a guidewire tubeport that includes a seal, with the guidewire tube extending through theseal of the guidewire tube port and into the exhaust lumen, wherein theseal includes a seal orifice that seals around a guidewire extendingthrough the guidewire tube port in the absence of the guidewire tube inthe guidewire tube port.

In some embodiments in which the catheter body includes a guidewire tubeport that includes a seal, with the guidewire tube extending through theseal of the guidewire tube port and into the exhaust lumen, theguidewire tube is removable from the guidewire tube port and the sealincludes a seal orifice that seals around a guidewire extending throughthe guidewire tube port after removal of the guidewire tube from theguidewire tube port.

In some embodiments in which the catheter body includes a guidewire tubeport that includes a seal, with the guidewire tube extending through theseal of the guidewire tube port and into the exhaust lumen, the fluidjet emanator includes a guidewire orifice, such that a guidewiredirected into the exhaust lumen from the distal end of the catheter bodyand advanced proximally toward the proximal end of the catheter bodypasses through the guidewire orifice before entering the distal port ofthe guidewire lumen.

In some embodiments in which the catheter body includes a guidewire tubeport that includes a seal, with the guidewire tube extending through theseal of the guidewire tube port and into the exhaust lumen, the distalend of the guidewire tube is located between the proximal end of thedistal body section and the fluid jet emanator.

In some embodiments in which the catheter body includes a guidewire tubeport that includes a seal, with the guidewire tube extending through theseal of the guidewire tube port and into the exhaust lumen, the proximalend of the guidewire tube is located in the proximal body section of thecatheter body.

In some embodiments in which the catheter body includes a guidewire tubeport that includes a seal, with the guidewire tube extending through theseal of the guidewire tube port and into the exhaust lumen, the proximalend of the guidewire tube is located in the proximal body section of thecatheter body and wherein the distal end of the guidewire tube islocated in the transition section.

In some embodiments in which the catheter body includes a guidewire tubeport that includes a seal, with the guidewire tube extending through theseal of the guidewire tube port and into the exhaust lumen, the cathetermay include one or more protrusions extending into the exhaust lumen ina direction transverse to the longitudinal axis.

In some embodiments in which the catheter body includes a guidewire tubeport that includes a seal, with the guidewire tube extending through theseal of the guidewire tube port and into the exhaust lumen, the distalend of the guidewire lumen is flared such that the distal port of theguidewire lumen is enlarged in a direction transverse to thelongitudinal axis.

In some embodiments of the catheters described herein, the catheter bodyincludes an outflow orifice and an inflow orifice, wherein at least aportion of pressurized fluid delivered to the fluid jet emanator throughthe fluid delivery tube emanates from the catheter body through theoutflow orifice, and wherein at least a portion of the fluid thatemanates from the catheter body through the outflow orifice re-entersthe catheter body through the inflow orifice, and further wherein theinflow orifice is located in the distal body section of the catheterbody. In some embodiments, both the outflow orifice and the infloworifice are located in the distal body section of the catheter.

In another aspect, the methods described herein may include a method ofthreading a guidewire into a catheter by inserting a proximal end of aguidewire into an exhaust lumen located proximate a distal end of acatheter; advancing the proximal end of the guidewire towards a proximalend of the catheter, wherein the guidewire advances through a guidewireorifice in a fluid emanator before entering a distal port of a guidewirelumen located within the exhaust lumen of the catheter; and advancingthe proximal end of the guidewire through the guidewire lumen, whereinthe proximal end of the guidewire exits the guidewire tube and thecatheter through a proximal port of the guidewire lumen.

In some methods described herein, the guidewire tube occupies only aportion of the length of the catheter.

In some methods described herein, the catheter body includes a guidewiretube port that includes a seal, wherein the guidewire tube extendsthrough the seal of the guidewire tube port and into the exhaust lumen,and the method includes removing the guidewire tube from the catheterafter the proximal end of the guidewire exits the guidewire tube and thecatheter through the proximal port of the guidewire lumen. In somemethods, the seal includes a seal orifice that seals around theguidewire after the guidewire tube has been removed from the guidewiretube port.

In some methods described herein, the catheter includes an elongatedcatheter body having a proximal end and a distal end, wherein alongitudinal axis extends between the proximal end and the distal end,and wherein the catheter body includes a proximal body section and adistal body section, wherein a distal end of the proximal body sectionis attached to a proximal end of the distal body section at a transitionsection of the catheter body; and wherein the exhaust lumen is locatedwithin the catheter body, the exhaust lumen being aligned with thelongitudinal axis, wherein the exhaust lumen has a proximalcross-sectional area on a proximal side of the transition section thatis larger than a distal cross-sectional area of the exhaust lumen on adistal side of the transition section. In further embodiments, thecatheter includes a fluid jet emanator located in the distal bodysection and a fluid delivery tube attached to the fluid jet emanator,the fluid delivery tube extending through at least a portion of theproximal body section, wherein the fluid delivery tube passes from theproximal body into the distal body section through the transitionsection.

The words “preferred” and “preferably” refer to embodiments of thecatheters and methods described herein that may afford certain benefits,under certain circumstances. However, other embodiments may also bepreferred, under the same or other circumstances. Furthermore, therecitation of one or more preferred embodiments does not imply thatother embodiments are not useful, and is not intended to exclude otherembodiments from the scope of the disclosure.

As used herein, “a,” “an,” “the,” “at least one,” and “one or more” areused interchangeably. Thus, for example, a seal may refer one seal ormore than one seal unless explicitly limited to, e.g., “only one seal.”

The term “and/or” means one or all of the listed elements or acombination of any two or more of the listed elements.

The above summary is not intended to describe each embodiment or everyimplementation of the present disclosure. Rather, a more completeunderstanding of the devices set forth in this disclosure will becomeapparent and appreciated by reference to the following DetailedDescription of Exemplary Embodiments and claims in view of theaccompanying figures of the drawings.

BRIEF DESCRIPTIONS OF THE VIEWS OF THE DRAWING

FIG. 1 depicts an exemplary embodiment of a system including anexemplary embodiment of a catheter as described herein.

FIG. 2 is an enlarged cross-sectional view of portions of one embodimentof a catheter as described herein.

FIG. 3 is a cross-sectional view the catheter depicted in FIG. 2 takenalong line 3-3 in FIG. 2.

FIG. 4 is a cross-sectional view the catheter depicted in FIG. 2 takenalong line 4-4 in FIG. 2.

FIG. 5 depicts a guidewire tube having a flared distal end.

FIG. 6 is a cross-sectional view the catheter depicted in FIG. 2 takenalong line 6-6 in FIG. 2.

FIG. 7 depicts one embodiment of a catheter described herein in usewithin a blood vessel.

FIG. 8 is an enlarged cross-sectional view of portions of anotherembodiment of a catheter as described herein.

FIG. 9 is an enlarged cross-sectional view of portions of anotherembodiment of a catheter as described herein.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

In the following detailed description of exemplary embodiments,reference is made to the accompanying figures of the drawing which forma part hereof, and in which are shown, by way of illustration, specificembodiments of the catheters and methods. It is to be understood thatother embodiments may be utilized and structural changes may be madewithout departing from the scope of the present disclosure.

FIG. 1 is a plan view that depicts a variety of components that may beprovided in a system that includes a catheter 10 as described herein.Embodiments of many of these components may be described in, e.g., USPatent Application Publication US 2008/0188831 A1, titled MINIATUREFLEXIBLE THROMBECTOMY CATHETER (Bonnette et al.).

Among the depicted components are a manifold 12 that is attached to aproximal end of the catheter 10. The manifold 12 may include a centraltubular body 16, an exhaust branch 18, and a high pressure connectionbranch 20 extending from the central tubular body 16. In the depictedembodiment, the proximal end of the catheter 10 is attached to themanifold 12 by the use of a Luer fitting 26 (although any other suitableconnection technique may be used). The proximal end of the catheter 10extends through a strain relief tube 28 and through the fitting 26 tocommunicate with the manifold 12.

The catheter 10 is shown engaged over and about a guidewire 104 wherethe guidewire 104 engages a lumen that opens at the distal end 37 of thecatheter 10 followed by passage proximally through the catheter 10 tothe location at which the guidewire 104 exits the catheter 10 asdiscussed in more detail herein. FIG. 1 also depicts a high pressurefluid source 106 and a high pressure fluid pump 110 connect, as shown,to the manifold 12 via the high pressure connection port 20 by connector22 (or optionally by a direct connection) to supply high pressure salineor other suitable fluid for the catheter 10. An optional exhaustregulator 112 and a collection chamber 114 connect to the exhaust branch18 of the manifold 12 by a fitting 19 (or optionally by directconnection) for influencing the outflow from the catheter 10. Examplesof some suitable systems including high pressure fluid sources and/orexhaust collection systems may be described in, e.g., U.S. Pat. No.6,805,684 (Bonnette et al.); U.S. Patent Application Publication No. US2007/0129679 (Bonnette et al.); etc.

The catheter 10 is constructed of tubular components including aproximal body section 30 joined and connected to a distal body section32 at a transition section 14. It may be preferred that proximal bodysection 30 and/or the distal body section 32 are constructed so as to beflexible enough to facilitate advancement of the catheter along a curvedpassageway such as, e.g., a blood vessel. The distal body section 32 maybe, but is not necessarily, shorter than the proximal body section 30.Either or both the proximal body section 30 and the distal body section32 may include multiple sub-sections having different external sizes. Insome embodiments, however, the distal body section 32 may preferablyhave a uniform external size (e.g., diameter for a circular body section32) from the distal end of the transition section 14 to at least thelocation of any inflow and/or outflow orifices (as described herein).

The tubular components of the catheter 10 may preferably be constructedof materials which promote pushability, torqueability, and which providefor operator feel. The proximal body section 30 may, for example, beconstructed of braided polyimide, a synthetic polymeric resin, metal(e.g., stainless steel, Nitinol, etc.) or any other suitable flexiblematerial(s), and the distal body section 32 may be constructed of Pebax,a thermoplastic elastomer, metal (e.g., stainless steel, Nitinol, etc.)or any other suitable material(s). The catheter 10 may preferablyinclude a hydrophilic coating to enhance deliverability along thevasculature or other structure. In some embodiments, e.g., thoseincluding metallic tubing, the tubing may include spiral cuts to improveflexibility.

The external body dimensions of the proximal body section 30 and thedistal body section 32 may preferably be selected such that the distalbody section 32 has smaller external dimensions than the proximal bodysection 30 to facilitate advancement of the distal body section 32 intosmaller passageways. In some embodiments, the proximal body section 30may have an external dimension of about 4 French (Fr) as measured withreference to the French catheter scale. The distal body section 32 mayinclude portions that have different external dimensions, whereby aproximal end of the distal body section tube 32 can, e.g., be 4 Fr sizeto mate with the distal end of the proximal tube 30. The more distallylocated portions of the distal body section 32 can be drawn and reducedor otherwise processed to reduce their external dimensions (to, e.g., a3 Fr size) to facilitate advancement of the distal body section 32 intosmaller passageways.

In some embodiments, the proximal body section 30 and the distal bodysection 32 are constructed of separate members that are attached to eachother within the transition section 14 by any suitable technique. Forexample, the proximal end of the distal body section 32 may be attachedto the distal end of the proximal body section 30 at a transitionsection 14 by drawing down the proximal end of the distal body section32 such that it can be inserted into the distal end of the proximal bodysection 30. The ends of the proximal body section 30 and the distal bodysection 32 can then be secured together by adhesive, welding, swaging,or by any other suitable method.

In other embodiments, the proximal body section 30 and the distal bodysection 32 may be formed of one continuous member that may be tapered orotherwise reduced in size at one or more transition sections such thatjoints between separate members may not be required.

Regardless of the specific construction details, the proximal bodysection 30 and the distal body section 32 preferably function togetheras an exhaust tube for evacuation of material, e.g., macerated effluencefrom a thrombus or lesion site. To do so, the distal body section 32 mayinclude one or more outflow orifices 36 a-36 n and one or more infloworifices 38 a-38 n, the use of which is described in more detail belowin connection with FIG. 7.

The catheters described herein may preferably be adapted to advancementto an internal body location using a guidewire that is threaded througha portion of the catheter. In some embodiments of thrombectomy cathetersand other devices that have been adapted for delivery over a guidewire,the structures used to guide the guidewire through the catheter can, insome instances, occupy significant portions of an interior lumen of thecatheter.

If the catheter is to be used for thrombectomy or other procedures inwhich the flow of fluid (e.g., saline) is used to remove materialthrough a lumen in the catheter as described in, e.g., U.S. PatentApplication Publication US 2008/0188831 A1, titled MINIATURE FLEXIBLETHROMBECTOMY CATHETER (Bonnette et al.), exhaust flow through the lumencan potentially be constricted by a guidewire tube that is located inthe smaller section of the catheter. In some instances, obstructions inthe smaller lumen, such as guidewire tubes, may result in reducedexhaust flow such that the net result is the infusion of fluid into thepassageway in which the catheter is located.

The catheters described herein, although they include guidewire tubesfor the guiding a guidewire within a portion of the catheter, include atruncated or shortened guidewire tube such that exhaust flow through thelumen in which the guidewire tube is located can be greater than acatheter including a guidewire tube that extend distally past a fluidjet emanator located in the distal body section of the catheter.

FIG. 2 is an enlarged cross-sectional view of selected portions of thecatheter 10 to illustrate various features of the catheters describedherein. The left-most selected portion of the catheter 10 depicted inFIG. 2 includes the proximal end 52 of the guidewire tube 50, while theright-most selected portion depicted in FIG. 2 includes a fluid jetemanator 60 and attached fluid delivery tube 62 that extends in theproximal direction through the catheter 10.

The center portion of the catheter 10 that is depicted in FIG. 2includes a transition section 14 between the proximal body section 30and the distal body section 32, along with the distal end 54 of theguidewire tube 50. FIG. 3 is a cross-sectional view taken within thecenter portion of FIG. 2 and includes the guidewire tube 50. The view ofFIG. 3 shows the distal port at the distal end of the guidewire tube 50that opens into the lumen 56 that extends through the guidewire tube 50to the proximal end 52 of the guidewire tube 50 (where the lumen 56preferably opens to the exterior of the catheter 10 at a proximal port).

FIGS. 2 and 3 also depict the optional guide structures 58 that may beprovided to assist in directing the proximal end of a guidewire (notshown) into the lumen 56 of the guidewire tube 50. In the depictedembodiment, the guide structures 58 may take the form of protrusionsthat may, for example, be formed as dents in the tubing of the proximalbody section 30. Although four guide structures 58 are depicted in FIGS.2 and 3, the catheters described herein may include any suitable numberof the guide structures, i.e., the catheters may include one, two,three, four, or more guide structures. It may be preferred that thedistal end 54 of the guidewire tube 50 be located proximally of theguide structures 58 as depicted in FIG. 2, although in some embodimentsthe guide structures 58 may be located around the distal end 54 of theguidewire tube 50.

Regardless of the exact nature of any guide structures used to helpdirect a guidewire into the guidewire tube 50, a balance will need to bemade between the ability of the guide structures to accomplish theirdirecting function and their impact on the fluid flow through theexhaust lumen 34.

As seen in the combination of the center portion and the left-mostportion of FIG. 2 and the cross-sectional view of FIG. 4, the guidewiretube 50 may preferably terminate at its proximal end 52 in an openingmade through a sidewall of the proximal body section 30 of the catheter10. In the depicted embodiment, the guidewire tube 50 may include a bendto achieve that function, with a bend being depicted in the left-mostportion of the FIG. 2. In other embodiments, the guidewire tube 50 maybe straight or nearly straight and may exit the proximal body section ofthe guidewire tube through a structure or structures as described inconnection with FIGS. 15-17 of US Patent Application Publication US2008/0188831 A1, titled MINIATURE FLEXIBLE THROMBECTOMY CATHETER(Bonnette et al.). Although the guidewire tube is depicted as ahomogeneous and unitary element, it may alternatively be constructed asa composite of multiple components so long as the components define alumen capable of guiding a guidewire through the tube from its distalend to its proximal end.

As depicted in FIGS. 2-3, the distal end 54 of the guidewire tube 50 maybe generally centered within the exhaust lumen 34. In some embodiments,however, the distal end 54 (and its corresponding distal port into theguidewire lumen 56) may not be centered within the exhaust lumen 34. Ifthe distal end of the guidewire tube 50 is not centered, any protrusionsor other guide structures that may be provided to direct a guidewireinto the guidewire tube 50 may also be adjusted accordingly.

As discussed herein, the guidewire tube 50 is located within only aportion of the catheter 10. Generally speaking, the guidewire tube 50may be described as having a distal end that terminates at a locationthat is proximal from the fluid jet emanator 60. In some embodiments,the distal end 54 of the guidewire tube 50 may be located between theproximal end of the distal body section 32 (where the proximal end is,e.g., located on the distal side of the transition section 14) and theproximal end 52 of the guidewire tube 50.

As depicted in FIG. 2, the proximal end 52 of the guidewire tube 50 maypreferably be located in the proximal body section 30 of the catheter10. In some embodiments, the distal end 54 of such a guidewire tube 50may preferably be located between the proximal end of the distal bodysection 32 (where the proximal end is, e.g., located on the distal sideof the transition section 14) and the proximal end 52 of the guidewiretube 50. Depending on the nature and construction of the transitionsection 14, the distal end 54 of the guidewire tube 50 may be locatedwithin the portion of the catheter 10 that is occupied by the transitionsection 14 between the proximal body section 30 and the distal bodysection 32.

In still other embodiments, the proximal end 52 of the guidewire tube 50may be described as being located in the proximal body section 30 of thecatheter 10 between the proximal end of the catheter 10 and thetransition section 14 between the proximal body section 30 and thedistal body section 32.

Among the features depicted in the various portions of FIG. 2 is theexhaust lumen 34 that extends through all of the portions of thecatheter 10. The exhaust lumen 34 has a proximal cross-sectional areawithin the proximal body section 30 (on the proximal side of thetransition section 14) that is larger than the cross-sectional area ofthe exhaust lumen 34 in the distal body section 32 (on the distal sideof the transition section 14). The exhaust lumen 34 may preferablyextend to the proximal end of the catheter 10 where is can be connectedto other components (e.g., the manifold 12) to remove material asdiscussed in, e.g., U.S. Patent Application Publication US 2008/0188831A1, titled MINIATURE FLEXIBLE THROMBECTOMY CATHETER (Bonnette et al.).

Another feature depicted in the various portions of FIG. 2 is the fluiddelivery tube 62 that is attached to the fluid jet emanator 60 depictedin the right-most portion of FIG. 2. The fluid delivery tube 62preferably extends through the exhaust lumen 34 in at least a portion ofboth the proximal body section 30 and the distal body section 32.Although not depicted in FIG. 2, the fluid delivery tube 62 may beconstructed of multiple components as discussed in, e.g., U.S. PatentApplication Publication US 2008/0188831 A1, titled MINIATURE FLEXIBLETHROMBECTOMY CATHETER (Bonnette et al.). Other examples of potentiallysuitable fluid jet emanators and fluid delivery tubes used to deliverfluid to them may be described in. e.g., U.S. Pat. No. 6,875,193(Bonnette et al.); U.S. Pat. No. 6,755,803 (Le et al.); U.S. PatentApplication Publication US 2006/0064123 A1 (Bonnette et al.); etc.

Yet another feature depicted in FIG. 2 is an outflow orifice 36 a and aninflow orifice 38 a, at least one of and/or both of which may, in someembodiments, be provided in the distal body section 32 of the catheter.The functions of the outflow orifice 36 a and the inflow orifice 38 awill be described in more detail herein with respect to FIG. 7 herein.

Another optional feature that may be provided in connection with thecatheters described herein is a funnel structure that may be attached tothe guidewire tube 150 itself to direct a guidewire into the distal endof the guidewire tube 150. One potentially suitable example of a funnelstructure is depicted in connection with FIG. 5 is in the form of aflared distal end 154 on the guidewire tube 150.

In place of or in addition to a funnel structure on the end of theguidewire tube, other structures such as cages, struts, etc. that extendoutwardly and serve to direct a guidewire into the guidewire tube mayalso be used. It may be beneficial if such structures include openings,notches, etc. such that fluid can flow through the guiding structureused.

Although no guide structures are depicted in the exhaust lumen 134defined by the body section 130 depicted in FIG. 5, guide structures(such as, e.g., the protrusions depicted in FIG. 3) may be provided inaddition to a funnel structure to further assist in directing aguidewire into the guidewire tube.

FIG. 6 is an enlarged cross-sectional view taken along line 6-6 in FIG.2 towards the distal end of the catheter 10 depicting the components ofthe fluid jet emanator 60 that are located within the distal bodysection 32 of the catheter 10. Among the features depicted in FIG. 6 arethe fluid delivery tube 62. The depicted fluid jet emanator 60 includesproximally directed jet orifices 64 a-64 n located on the proximal sideof the fluid jet emanator 60 for the creation of a cross stream jetincorporating the outflow orifices 36 a-36 n (see, e.g., FIGS. 1 and 7)and inflow orifices 38 a-38 n of the catheter 10. The outflow orifices36 a-36 n, as well as the inflow orifices 38 a-38 n, may be spacedaround the catheter at, e.g., 120.degree. intervals or other suitableintervals.

Although the fluid jet emanator 60 is in the form of an arcuateforeshortened loop which at least partially defines a guidewire orificewithin the lumen 34 that allows the passage of a guidewire through theloop and the lumen 34 in the proximal direction. The fluid jet emanatorsused in connection with the catheters described herein may take avariety of other forms (i.e., they are not limited to the arcuate loopdepicted in FIG. 6), for example, the fluid jet emanators may be in theform of a larger loop (e.g., a 350+ degree loop) or otherbodies/structures that do not include arcuate tubing (such as the fluidjet emanators described in, e.g., U.S. Patent Application Publication US2006/0064123 A1 (Bonnette et al.).

The fluid jet emanator 60 depicted in FIGS. 2 and 6 may rest against orotherwise be supported by a support ring 66 located on the distal sideof the fluid jet emanator 60. The support ring 66 may preferably includea guidewire orifice 67 to allow a guidewire that is inserted into thedistal end of the catheter 10 to pass through the support ring 66. Thefluid jet emanator 60 also preferably allows the guidewire to beadvanced in the proximal direction towards the guidewire tube asdiscussed herein. If a fluid jet emanator is used in catheters such asthose described herein that is not in the form an arcuate tube, then thefluid jet emanator itself may include a guidewire orifice (see, e.g.,passageway 104 in FIGS. 13-14 of U.S. Patent Application Publication US2006/0064123 A1 (Bonnette et al.)).

FIGS. 1 and 7 can be used to describe one mode of operation of onecatheter as described herein, where FIG. 1 illustrates the catheter 10connected to the various components of the system, and where FIG. 7illustrates a side view of the distal region of the catheter 10 in theperformance of a method of using the catheter 10 within a small bloodvessel 100 (shown in cross section) at a site of a thrombotic deposit orlesion 102.

In FIG. 1, the rapid exchange catheter 10 is shown engaged over andabout a guidewire 104 where the guidewire 104 (previously located in theblood vessel 100 of FIG. 7) first engages the catheter 10 at itsoptional flexible distal tip 37 followed by exiting from the guidewiretube (see, e.g., guidewire tube 50 in FIG. 2). FIG. 7 is a side view ofthe distal portion of the catheter 10 in the performance of oneillustrative method of use. Generally, the guidewire 104 is deployed ina blood vessel 100 (or other lumen) before introducing the catheter 10.Any suitable guidewire may be used, e.g., a normal guidewire, a filterguidewire, a balloon occlusion guidewire, etc.

The catheter 10, with its components (e.g., fluid delivery tube, fluidjet emanator, etc.) is advanced over and along the guidewire 104 whichis aligned within the blood vessel 100 for, in the depicted embodiment,the purpose of debris/thrombus/lesion removal and maneuvered into anappropriate position for treatment. In some embodiments, othertherapies/treatments may be provided, e.g., drug infusion, etc.

In some embodiments, a guide catheter or sheath can be used inconnection with catheter 10 to provide assistance in placing thecatheter 10 within the desired location of the blood vessel 100 in orderthat the tapered tip 37 of the catheter 10 can be advanced through thethrombus or lesions 102 to position the fluid jet emanator in very closeproximity to the thrombus or lesions 102. Although depicted in onelocation in FIG. 7, the catheter 10 may be moved proximally or distallyduring the procedure to maximize the effect of the catheter system.Further interventions can be executed as normal over the remainingguidewire or guidewire device.

FIG. 7 is a side view, in partial cross section, of the catheter 10 inthe performance of one embodiment of a method as described herein. Asdiscussed, the catheter 10 is engaged over and about the guidewire 104wherein the guidewire 104 (which may have been previously inserted intothe body lumen, e.g., a vein, artery, etc.) can first slideably passthrough a passageway provided through the optional tapered flexible tip37. The guidewire 104 enters the catheter 10, where it is located withinthe exhaust lumen 34 after passing through the fluid jet emanatorlocated within the catheter 10 (see, e.g., FIGS. 2 and 6 for views ofsome embodiments of fluid jet emanators that may be used in catheter10). The guidewire 104 is directed in the proximal direction through theexhaust lumen 34 past the inflow orifices 38 a-38 n and the outfloworifices 36 a-36 n.

The pressurized fluid (e.g., saline or other suitable fluids such asdrugs, etc.) delivered to the fluid jet emanator in the catheter 10, incombination with the outflow orifices 36 a-36 n and inflow orifices 38a-38 n, preferably produces non-hemolyzing cross stream jets 120 ofsaline or other suitable fluids which emanate from the outflow orifices36 a-36 n to accomplish thrombectomy functions, as described herein.Cross stream jets 120 with characteristics that fall short of hemolysisby, e.g., controlling the input fluid pressure at the high pressurefluid pump 110 and/or by controlling the exhaust rate at the exhaustregulator 112, whereby the exhaust regulator 112 may be operated to,e.g., provide a negative pressure for effluent aspiration.

The cross stream jets 120 emanating from the outflow orifices 36 a-36 nprovide for the fluid jet impingement of the deposits of thrombus orlesions 102 on the inner wall of the blood vessel 100 adjacent to or inclose proximity to the orifices 36 a-36 n in order to impinge, ablateand loosen deposits of thrombus or lesions 102, whereby such thrombus orlesion particulate and fluids can be entrained through one or moreinflow orifices 38 a-38 n by aspiration into the exhaust lumen 34 andremoved proximally through the exhaust lumen 34 using, e.g., an exhaustregulator 112. In some embodiments, manual aspiration methods couldpotentially be used as well. Although multiple inflow orifices 38 a-38 nare found in the depicted embodiment, as few as one inflow orifice maybe provided in some embodiments.

In some embodiments, drugs for treatment or for lysing of the thrombusor lesions 102 can also be delivered via the outflow orifices 36 a-36 nto, e.g., soften the deposits of thrombus or lesions 102 in the regionof the blood vessel 100 adjacent to or in close proximity to the outfloworifices 36 a-36 n. Any such drugs may, e.g., be delivered through thefluid delivery tube delivering fluid to the fluid jet emanator, througha separate lumen, using a different fluid delivery device (e.g.,catheter, etc.).

As depicted in FIG. 7, multiple high velocity fluid jet streams 118 of asuitable fluid (e.g., saline, etc.) are shown being emitted in aproximal direction from the fluid jet emanator 60 to form thecross-stream jets 120 that impinge upon and carry away thromboticdeposits or lesions 102 as particles 102 a. Other fluid jet emanators ofappropriate size and/or configuration can be incorporated within thedistal portion of the distal body section 32 as an alternative to thefluid jet emanator 60 illustrated in this figure to emanate or emit oneor more fluid jet streams to accomplish the same purpose as thatdescribed for the fluid jet emanator 60.

In the depicted embodiment, the high velocity fluid jet streams 118 passoutwardly through the outflow orifices 36 a-36 n in a radial direction,thereby creating cross stream jets 120 (lower velocity jets) directedoutwardly toward the wall of the blood vessel 100 and are influenced bythe low pressure at the inflow orifices 38 a-38 n to cause the crossstream jets 120 to flow circumferentially and distally to impinge on,provide drag forces on, and break up thrombotic deposits or lesions 102and to, by entrainment, urge and carry along the particles 102 a ofthrombotic deposits or lesions 102 through the inflow orifices 38 a-38n, a relatively low pressure region, into the high velocity fluid jetstreams 118 where the thrombus is further macerated into microscopicparticles, and then into the exhaust lumen 34 of the distal body section32 (see, e.g., FIG. 2).

A certain portion of this macerated debris which is mixed with freshfluid provided through the fluid jet emanator is removed through theexhaust lumen 34 and a certain portion flows back out the outfloworifices 36 a-36 n and recirculates to break up more debris which isreturned to the inflow orifices 38 a-38 n. In this way, more fluid flowmay circulate through the system than is injected through the jetemanator. For purposes of illustration and example, in some embodimentsthree to ten times more flow circulates through the system than isdelivered by the jet emanator. The entrainment through the infloworifices 38 a-38 n is based on entrainment by the high velocity fluidjet streams 118. The outflow is driven by internal pressure which iscreated by the high velocity fluid jet streams 118 and the fluidentrained through the inflow orifices 38 a-38 n.

Enhanced clot removal may be attainable because of the recirculationpattern established between outflow and inflow orifices 36 a-36 n and 38a-38 n, which may create a flow field that increases drag force onwall-adhered thrombus. Since the entrained thrombus is macerated intomicroscopic particles 102 a, those particles that exit the outfloworifices 36 a-36 n are preferably not of sufficient size tosignificantly block the distal circulation, and will often bere-entrained into the inflow orifices 38 a-38 n at a high rate. In ano-flow situation or when flow is stopped with another device, such asan occlusive balloon, material can be recirculated and rediluted untilall that remains is saline and all particles are removed.

The sizing of the various components used in connection with the systemsand methods described herein may vary based on a number of factors suchas, e.g., size of the catheter, materials to be removed using thecatheter, fluid flow rates desired, etc. In general, however, jetorifices in the fluid jet emanators can range in size, e.g., from 0.001inch to 0.040 inch for emanation of saline or other suitable fluidtherefrom in a velocity range of 1 to 250 m/s. By sizing the jetorifices and adjusting the high pressure fluid pump, the velocity andstrength of the cross stream fluid flow can be controlled. The generaloperating pressures of the catheter system may, for example, range from50 psi to 20,000 psi. The fluid delivery tubes may, in one embodiment,be circular tubes with an outside diameter of about 0.018 inch and ininside diameter of about 0.012 inch over a proximal portion, and anoutside diameter of about 0.011 inch and an inside diameter of about0.008 inch over an intermediate portion, and an outside diameter ofabout 0.007 inch and an inside diameter of about 0.004 inch over adistal portion, although other tube profiles and/or dimensions may beused.

The catheter body sections may have a variety of different tubularprofiles and/or dimensions, although in some embodiments, the distalbody sections attached to the distal ends of the transition sections maybe circular in profile and have an outside diameter of about 0.039 inch,(corresponding to an external size of 3 French), and an inside diameterof about 0.033 inch. The proximal body sections attached to the proximalends of the transition sections may have a circular profile with anoutside diameter of about 0.052 inch (corresponding to an external sizeof 4 French), and an inside diameter of about 0.046 inch.

The guidewire tubes may also vary in size, although in some embodiments,the guidewire tube may be provided in the form of a circular tube thathas in outside diameter of about 0.0205 inch and an inside diameter ofabout 0.0165 inch. Other guidewire tubes having different profilesand/or dimensions may be used. The length of the guidewire tube may varydepending on the selected locations for its proximal and distal ends.

Another embodiment of a catheter that may be used as described herein isdepicted in the cross-sectional view of FIG. 8 (which is similar in manyrespects to the view seen in FIG. 2). One difference between thecatheter 10 of FIG. 2 and the catheter 210 of FIG. 8 is that thetransition section 214 of catheter 210 is longer as compared to thetransition section 14 seen in FIG. 2. The transition section 214 isstill located between a proximal body section 230 and a distal bodysection 232. In one embodiment, the longer transition section may have alength of about 2.5 centimeters (cm), although in some embodiments, theguidewire tube may have a length of about 1 cm or longer, 2 cm orlonger, etc.

In the embodiment depicted in FIG. 8, the guide structure 258 is in theform of a annular protrusion that extends into the exhaust lumen 234 (incontrast to the discrete protrusions 58 described in connection withcatheter 10). The annular protrusion 258 may extend completely aroundthe perimeter of the catheter 210 or it may extend only partially aroundthe perimeter.

Although the annular protrusion 258 is located in the transition section214, it may alternatively be located more distally or proximally. Theprotrusion 258′ depicted in broken lines in FIG. 8 is an example of amore distally located protrusion. The protrusion 258′ is locateddistally from the transition section 214 and, as a result, can bedescribed as being located in the distal body section 232 of thecatheter 210. In such an embodiment, the guidewire tube 250 may alsoextend further such that its distal end 254′ (depicted in broken linesin FIG. 8) is located distally from the proximal end of the distal bodysection 232 (i.e., the distal end 254′ of the guidewire tube 250 islocated in the distal body section 232 of the catheter 210). In stillother embodiments, any protrusions and the distal end of the guidewiretubes may be located entirely within the proximal body section 230 suchthat neither protrusions or the guidewire tube are located in thetransition section or the distal body section.

Another optional feature in the embodiment depicted in FIG. 8 is thatthe guidewire tube 250 may also include a restriction 253 locatedbetween its proximal end 252 and its distal end 254. The restriction 253preferably reduces the size of the lumen 256 at a location proximal fromthe distal end 254 of the guidewire tube 250. Such a restriction 253 mayserve to reduce flow through the guidewire tube 250 as liquid and othermaterials flow in the proximal direction through the exhaust lumen 234while not unduly restricting the ability of a guidewire to enter thedistal end 254 of the guidewire lumen 250.

The restriction 253 may take any of a number of forms. Some potentiallysuitable examples may include, but are not limited to, one or moreprotrusions into the lumen of the guidewire tube (similar to, e.g.,protrusions 58 and 258 described herein), a necked-down section, a pluglocated in the guidewire tube 250 (with the plug retaining a passagewaytherethrough to allow a guidewire to pass through the restriction), etc.If a plug is used, it may be constructed of any suitable material(s),e.g., silicone, urethane, metal, etc.

Another embodiment of a catheter 310 is depicted in FIG. 9 and includesa proximal body section 330 connected to a distal body section 332through a transition section 314. A fluid jet emanator 360 is providedand attached to a fluid delivery tube 362 that extends proximallythrough the exhaust lumen 334 in the catheter 310.

Also provided in the embodiment depicted in FIG. 9 is a guidewire tube350 that extends into the exhaust lumen 334 through a guidewire tubeport 370. The guidewire tube 350 may preferably extend through theexhaust lumen 334 such that its distal end 354 is located on theproximal side of the fluid jet emanator 360.

The guidewire tube 350 in the embodiment depicted in FIG. 9 ispreferably removable from the exhaust lumen 334 by withdrawing itthrough the port 370 in the direction of arrow 374. It may be preferredto use a guidewire tube with smaller dimensions than the guidewire tubesthat remain in place. For example, a removable guidewire tube may have acircular profile with an outside diameter of about 0.0205 inch and aninside diameter of about 0.0155 inch or, in another embodiment, outsidediameter of about 0.019 inch and an inside diameter of about 0.0155inch. Other guidewire tubes having different profiles and/or dimensionsmay be used.

The guidewire tube port 370 preferably includes a seal 372 such that,upon removal of the guidewire tube 350, the port 370 can besubstantially closed. If the guidewire 304 is left in place such that itextends through the port 370 after removal of the guidewire tube 350,then the seal 372 may preferably seal around the guidewire 304. The seal372 may not necessarily need to form a fluid-tight seal in or over theport 370. In other words, the seal 372 may only serve to substantiallyclose the port 370 after removal of the guidewire tube 350. The seal 370may take a wide variety of forms, although it may preferably be formedof a flexible, resilient material, e.g., silicone, urethane, etc. It maybe in the form of an O-ring, one or more flaps, etc.

By removing the guidewire tube 350, flow through the exhaust lumen 334may be enhanced and, in addition, placement of the distal end 354 of theguidewire tube 350 adjacent the fluid jet emanator 360, advancement ofthe guidewire 304 into the guidewire tube 350 may be improved and/orsimplified.

The complete disclosure of the patents, patent documents, andpublications cited in the Background, the Detailed Description ofExemplary Embodiments, and elsewhere herein are incorporated byreference in their entirety as if each were individually incorporated.

Exemplary embodiments of catheters and methods have been discussed andreference has been made to possible variations within the scope of thisdisclosure. These and other variations and modifications in thedisclosure will be apparent to those skilled in the art withoutdeparting from the scope of the disclosure, and it should be understoodthat this disclosure is not limited to the illustrative embodiments setforth herein. Accordingly, the disclosure is to be limited only by theclaims provided below and equivalents thereof.

1-15. (canceled)
 16. A method of threading a guidewire into a catheter,the method comprising: inserting a proximal end of a guidewire into anexhaust lumen located proximate a distal end of a catheter; advancingthe proximal end of the guidewire towards a proximal end of thecatheter, wherein the guidewire advances through a guidewire orifice ina fluid emanator before entering a distal port of a guidewire lumenlocated within the exhaust lumen of the catheter; and advancing theproximal end of the guidewire through the guidewire lumen, wherein theproximal end of the guidewire exits the guidewire tube and the catheterthrough a proximal port of the guidewire lumen.
 17. A method accordingto claim 16, wherein the guidewire tube occupies only a portion of thelength of the catheter.
 18. A method according to claim 16, wherein thecatheter body comprises a guidewire tube port that comprises a seal,wherein the guidewire tube extends through the seal of the guidewiretube port and into the exhaust lumen, and wherein the method comprises:removing the guidewire tube from the catheter after the proximal end ofthe guidewire exits the guidewire tube and the catheter through theproximal port of the guidewire lumen.
 19. A method according to claim16, wherein the catheter comprises an elongated catheter body comprisinga proximal end and a distal end, wherein a longitudinal axis extendsbetween the proximal end and the distal end, and wherein the catheterbody comprises a proximal body section and a distal body section,wherein a distal end of the proximal body section is attached to aproximal end of the distal body section at a transition section of thecatheter body; and wherein the exhaust lumen is located within thecatheter body, the exhaust lumen being aligned with the longitudinalaxis, wherein the exhaust lumen comprises a proximal cross-sectionalarea on a proximal side of the transition section that is larger than adistal cross-sectional area of the exhaust lumen on a distal side of thetransition section.
 20. A method according to claim 18, wherein thecatheter comprises a fluid jet emanator located in the distal bodysection and a fluid delivery tube attached to the fluid jet emanator,the fluid delivery tube extending through at least a portion of theproximal body section, wherein the fluid delivery tube passes from theproximal body into the distal body section through the transitionsection.
 21. A catheter comprising: an elongated catheter bodycomprising a proximal end and a distal end, wherein a longitudinal axisextends between the proximal end and the distal end, and wherein thecatheter body comprises a proximal body section and a distal bodysection, wherein a distal end of the proximal body section is attachedto a proximal end of the distal body section at a transition section ofthe catheter body; an exhaust lumen located within the catheter body,the exhaust lumen being aligned with the longitudinal axis, wherein theexhaust lumen comprises a proximal cross-sectional area on a proximalside of the transition section that is larger than a distalcross-sectional area of the exhaust lumen on a distal side of thetransition section; one or more protrusions extending into the exhaustlumen in a direction transverse to the longitudinal axis; a fluid jetemanator located in the distal body section; a fluid delivery tubeattached to the fluid jet emanator, the fluid delivery tube extendingthrough at least a portion of the proximal body section, wherein thefluid delivery tube passes from the proximal body section into thedistal body section through the transition section; and a guidewire tubelocated within only a portion of the catheter body, wherein theguidewire tube comprises a proximal end and a distal end, wherein theguidewire tube comprises a guidewire lumen extending from a proximalport at the proximal end of the guidewire tube to a distal port at thedistal end of the guidewire tube, and wherein the distal port of theguidewire lumen opens into the exhaust lumen at a location proximal fromthe fluid jet emanator.
 22. A catheter according to claim 21, whereinthe one or more protrusions comprise one protrusion that extendsannularly around a diameter of the catheter.
 23. A catheter according toclaim 21, wherein the one or more protrusions comprise more than oneprotrusion that extends annularly around a diameter of the catheter. 24.A catheter according to claim 23, wherein said protrusions each extend alength that is less than the diameter of the catheter.
 25. A cathetercomprising: an elongated catheter body comprising a proximal end and adistal end, wherein a longitudinal axis extends between the proximal endand the distal end, and wherein the catheter body comprises a proximalbody section and a distal body section, wherein a distal end of theproximal body section is attached to a proximal end of the distal bodysection at a transition section of the catheter body; an exhaust lumenlocated within the catheter body, the exhaust lumen being aligned withthe longitudinal axis, wherein the exhaust lumen comprises a proximalcross-sectional area on a proximal side of the transition section thatis larger than a distal cross-sectional area of the exhaust lumen on adistal side of the transition section; a fluid jet emanator located inthe distal body section; a fluid delivery tube attached to the fluid jetemanator, the fluid delivery tube extending through at least a portionof the proximal body section, wherein the fluid delivery tube passesfrom the proximal body into the distal body section through thetransition section; a guidewire tube located within only a portion ofthe catheter body, wherein the guidewire tube comprises a proximal endand a distal end, wherein the guidewire tube comprises a guidewire lumenextending from a proximal port at the proximal end of the guidewire tubeto a distal port at the distal end of the guidewire tube, and whereinthe distal port of the guidewire lumen opens into the exhaust lumen at alocation proximal from the fluid jet emanatory and further comprisingone or more restrictions extending into the guidewire lumen in adirection transverse to the longitudinal axis.
 26. A catheter accordingto claim 25, wherein the one or more restrictions comprise onerestriction that extends annularly around a diameter of the catheter.27. A catheter according to claim 25, wherein the one or morerestrictions comprise more than one restriction that extends annularlyaround a diameter of the catheter.
 28. A catheter according to claim 27,wherein each restriction extends a length that is less than the diameterof the catheter.